1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
//******************************************************************************
//
// File: SharedLongArrayReductionBuf.java
// Package: edu.rit.mp.buf
// Unit: Class edu.rit.mp.buf.SharedLongArrayReductionBuf
//
// This Java source file is copyright (C) 2007 by Alan Kaminsky. All rights
// reserved. For further information, contact the author, Alan Kaminsky, at
// ark@cs.rit.edu.
//
// This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
// software; you can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// PJ is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
// A PARTICULAR PURPOSE. See the GNU General Public License for more details.
//
// Linking this library statically or dynamically with other modules is making a
// combined work based on this library. Thus, the terms and conditions of the
// GNU General Public License cover the whole combination.
//
// As a special exception, the copyright holders of this library give you
// permission to link this library with independent modules to produce an
// executable, regardless of the license terms of these independent modules, and
// to copy and distribute the resulting executable under terms of your choice,
// provided that you also meet, for each linked independent module, the terms
// and conditions of the license of that module. An independent module is a
// module which is not derived from or based on this library. If you modify this
// library, you may extend this exception to your version of the library, but
// you are not obligated to do so. If you do not wish to do so, delete this
// exception statement from your version.
//
// A copy of the GNU General Public License is provided in the file gpl.txt. You
// may also obtain a copy of the GNU General Public License on the World Wide
// Web at http://www.gnu.org/licenses/gpl.html.
//
//******************************************************************************
package edu.rit.mp.buf;
import edu.rit.mp.Buf;
import edu.rit.mp.LongBuf;
import edu.rit.pj.reduction.LongOp;
import edu.rit.pj.reduction.Op;
import edu.rit.pj.reduction.SharedLongArray;
import edu.rit.util.Range;
import java.nio.ByteBuffer;
/**
* Class SharedLongArrayReductionBuf provides a reduction buffer for class
* {@linkplain SharedLongArrayBuf}.
*
* @author Alan Kaminsky
* @version 26-Oct-2007
*/
class SharedLongArrayReductionBuf
extends SharedLongArrayBuf
{
// Hidden data members.
LongOp myOp;
// Exported constructors.
/**
* Construct a new shared long array reduction buffer.
*
* @param theArray Shared array.
* @param theRange Range of array elements to include in the buffer.
* @param op Binary operation.
*
* @exception NullPointerException
* (unchecked exception) Thrown if <TT>op</TT> is null.
*/
public SharedLongArrayReductionBuf
(SharedLongArray theArray,
Range theRange,
LongOp op)
{
super (theArray, theRange);
if (op == null)
{
throw new NullPointerException
("SharedLongArrayReductionBuf(): op is null");
}
myOp = op;
}
// Exported operations.
/**
* Store the given item in this buffer.
* <P>
* The <TT>put()</TT> method must not block the calling thread; if it does,
* all message I/O in MP will be blocked.
*
* @param i Item index in the range 0 .. <TT>length()</TT>-1.
* @param item Item to be stored at index <TT>i</TT>.
*/
public void put
(int i,
long item)
{
myArray.reduce (myArrayOffset+i*myStride, item, myOp);
}
/**
* Create a buffer for performing parallel reduction using the given binary
* operation. The results of the reduction are placed into this buffer.
*
* @param op Binary operation.
*
* @exception ClassCastException
* (unchecked exception) Thrown if this buffer's element data type and
* the given binary operation's argument data type are not the same.
*/
public Buf getReductionBuf
(Op op)
{
throw new UnsupportedOperationException();
}
// Hidden operations.
/**
* Receive as many items as possible from the given byte buffer to this
* buffer.
* <P>
* The <TT>receiveItems()</TT> method must not block the calling thread; if
* it does, all message I/O in MP will be blocked.
*
* @param i Index of first item to receive, in the range 0 ..
* <TT>length</TT>-1.
* @param num Maximum number of items to receive.
* @param buffer Byte buffer.
*
* @return Number of items received.
*/
protected int receiveItems
(int i,
int num,
ByteBuffer buffer)
{
int index = i;
int off = myArrayOffset + i * myStride;
int max = Math.min (i + num, myLength);
while (index < max && buffer.remaining() >= 8)
{
myArray.reduce (off, buffer.getLong(), myOp);
++ index;
off += myStride;
}
return index - i;
}
}
|
